This invention relates to infusion site leak detection systems and, in particular embodiments, to leak detection systems that detect when fluid is leaking under a delivery device, such as an infusion pump or an infusion set, near an infusion site.
Continuous subcutaneous infusion of medications is becoming increasingly important. Typically, an individual uses a small pager size programmable pump to deliver a medication through a flexible plastic tube to an infusion set. The infusion set delivers medication to an individual""s subcutaneous tissue through the use of either a rigid needle that is left in the tissue or through a flexible cannula that remains in the tissue after being inserted via a removable needle. The most common infused fluid is insulin. Currently, more than 70,000 individuals in the U.S., and about 30,000 more individuals worldwide, use subcutaneous infusion of insulin for the treatment of diabetes mellitus. However, other infused fluids include HIV drugs, drugs to treat pulmonary hypertension, iron chelation drugs, pain medications, and anti-cancer treatments.
Generally, one end of the cannula is attached to the infusion set and the other end is inserted through the individual""s skin. An adhesive pad on a bottom of the infusion set adheres the infusion set to the individual""s skin. Clear adhesive tape is often placed over the infusion set and in contact with the individual""s skin to further secure the infusion set and cannula.
A leak near the infusion site can be one of the most serious problems that occurs while infusing a medication. Traditionally, leaks near the infusion site are caused by inadvertently pulling the cannula out of the body, or separating the cannula from an infusion set, or an inadequately sealed infusion set. A medication leaking near the insertion site is often trapped by the adhesive and collects between the infusion set and the skin. And, even though the infusion set is typically made of clear plastic, it is hard for the individual to look at the infusion set and tell the difference between medication passing through the infusion set, and medication collecting under the infusion set. Also, most infused medications are delivered at a rate as low as a few micro liters per hour (xcexcl/Hr.). This delivery rate is so slow that individuals typically cannot discern between body moisture, such as sweat, and medication that has leaked onto the surface of their skin near the infusion site. Thus, hours may pass before a medication begins to seep out from under the adhesive pad and drip down the individual""s skin, drawing their attention to the leak. In the meantime, the individual may suffer significant consequences due to the lack of medication in their system. In the case of a diabetic individual infusing insulin, for example, the user could pass out due to hyperglycemia before realizing that insulin is not entering their body.
According to an embodiment of the invention, a leak detection system is to detect the presence of a fluid to be delivered into an individual""s body that has leaked near an infusion site. Embodiments of the present invention include a delivery device, a delivery element and at least one chemical. The delivery device is adapted for attachment to the individual""s body. The delivery element is configured to penetrate the individual""s body at the infusion site and establish fluid communication between the delivery device and the individual""s body, so that the fluid can travel from the delivery device into the individual""s body. The at least one chemical is positioned near the infusion site and reacts with at least one component within the fluid when the fluid is present near the infusion site.
In particular embodiments, a product of a chemical reaction, between the at least one chemical positioned near the infusion site and the at least one component within the fluid, is a colored complex. In specific embodiments, the at least one chemical positioned near the infusion site contains at least 4-amino-antipyrine and potassium ferricyanide. In other embodiments, the at least one chemical positioned near the infusion site contains at least 4-amino-antipyrine and potassium ferricyanide and horse radish peroxidase (HRP). Alternatively, the at least one chemical positioned near the infusion site contains at least ninhydrin. In additional embodiments, the at least one chemical positioned near the infusion site contains at least Coomassie Brilliant Blue.
Various methods may be used to position the at least one chemical near the infusion site. In some embodiments, the at least one chemical positioned near the infusion site is encapsulated in micro-spheres. In other embodiments, the at least one chemical positioned near the infusion site is a component of a gel. In further embodiments, the at least one chemical positioned near the infusion site is a component of an adhesive. And in still further embodiments, the at least one chemical positioned near the infusion site is associated with starch granules. In particular embodiments, the delivery device includes a base, and the at least one chemical positioned near the infusion site is embedded in the base of the delivery device. Finally, in other embodiments, the at least one chemical positioned near the infusion site is deposited on the individual""s body.
In particular embodiments, the delivery device is an infusion set. In other embodiments, the delivery device is an infusion pump.
According to another embodiment of the invention, a leak detection system to detect the presence of a fluid to be delivered into an individual""s body that has leaked near an infusion site includes a delivery device, a delivery element, an adhesive tape, and at least one chemical. The delivery device is adapted for attachment to the individual""s body. The delivery element is configured to penetrate the individual""s body at the infusion site and establish fluid communication between the delivery device and the individual""s body, so that the fluid can travel from the delivery device into the individual""s body. The adhesive tape is applied to a portion of the individual""s body to hold the delivery device on the individual""s body. The at least one chemical is associated with the adhesive tape and reacts with at least one component within the fluid when the fluid is present near the infusion site.
In particular embodiments, a product of a chemical reaction between the at least one chemical associated with the adhesive tape, and the at least one component within the fluid, is a colored complex. In additional embodiments, the at least one chemical associated with the adhesive tape is included with the adhesive on the adhesive tape.
According to a further embodiment of the invention, the leak detection system, to detect the presence of a fluid to be delivered into an individual""s body that has leaked near an infusion site, includes a delivery device, a delivery element, at least one chemical, an optical receiver, and a light conducting element. The delivery device is adapted for attachment to the individual""s body. The delivery element is configured to penetrate the individual""s body at the infusion site and establish fluid communication between the delivery device and the individual""s body, so that the fluid can travel from the delivery device into the individual""s body. The at least one chemical is positioned near the infusion site, and reacts with at least one component within the fluid when the fluid is present near the infusion site. A product of a chemical reaction between the at least one chemical positioned near the infusion site and the at least one component within the fluid is a colored complex. The light conducting element guides light from a point near the infusion site to the optical receiver. The optical receiver detects a change in light when the colored complex is created by the chemical reaction and provides an output signal indicating that a leak is detected. In particular embodiments, the light conducting element is at least one fiber optic cable. In alternative embodiments, the light conducting element is a flexible plastic tube filled with the fluid. In particular embodiments, the leak detection system includes an alarm system, controlled by the output signal, to notify the individual when a leak is detected. In more particular embodiments, the alarm system produces an audible sound when a leak is detected, and in other embodiments, the alarm system activates a vibrator when a leak is detected.
According to yet another embodiment of the invention, a leak detection system to detect the presence of a fluid to be delivered into an individual""s body that has leaked near an infusion site includes a delivery device, a delivery element, a rosette, at least one electrical component, and a battery. The delivery device is adapted for attachment to the individual""s body, and the delivery device includes a delivery device base. The delivery element is configured to penetrate the individual""s body at the infusion site and establish fluid communication between the delivery device and an individual""s body, so that the fluid can travel from the delivery device into the individual""s body. The rosette is positioned on the delivery device base and substantially surrounds the delivery element. The at least one electrical component is coupled to the rosette and detects a change in at least one electrical characteristic associated with the rosette when a leak occurs. The battery supplies power to the at least one electrical component.
In particular embodiments, the rosette is a closed circuit, and the impedance across the rosette decreases as fluid leaks near the infusion site. In alternative embodiments, the rosette is a closed circuit before a leak occurs, and at least portions of the rosette dissolve in the presence of the fluid. The impedance across the rosette increases as the at least portions of the rosette dissolve. In other particular embodiments, the rosette is an open circuit, and the circuit is closed when fluid leaks near the infusion site. In alternative particular embodiments, one or more chemicals are positioned near the infusion site, and leaking fluid near the infusion site triggers an electrochemical reaction with the chemicals.
In particular embodiments, the at least one electrical component measures voltage across the rosette. In other particular embodiments, the at least one electrical component measures impedance across the rosette. In still other embodiments, the at least one electrical component measures capacitance across the rosette.
In particular embodiments, the leak detection system includes an alarm system, coupled to the battery and to the at least one electrical component, to notify and indicate when a leak is detected. The alarm system produces an audible sound when a leak is detected. In alternative embodiments, the alarm system activates a vibrator when a leak is detected.
According to an embodiment of the invention, a leak detection system to detect the presence of a fluid to be delivered into an individual""s body that has leaked near an intended delivery site includes a delivery attachment element, a delivery element, and at least one reactive element. The delivery attachment element is adapted for attachment to the delivery site and the delivery element. The delivery element is configured to penetrate the delivery site and establish fluid communication between the delivery attachment element and the individual""s body, so that the fluid can travel from the delivery attachment element and into the individual""s body. The at least one reactive element is positioned near the delivery site and coupled to at least one of, the delivery attachment element and the delivery element, so that when the fluid is present near the delivery site, the at least one reactive element reacts with at least one component within the fluid.